Panel Lamps Dimmer Circuit

Panel Lamp Dimmer Components

Power and Ground

All lamps in the panel lamps dimmer circuits are provided a path to ground at all times through a hardwired ground circuit.
These lamps are illuminated by a 12 volt PWM output of the BCM or the door control modules through several panel lamps dimmer circuits.

Panel Lamp Dimmer Circuit Operation

The shared PWM output synchronizes the selected illumination intensity level of all the lamps in the panel lamps dimmer circuits.
The BCM uses hardwired resistor Multiplexed (MUX) inputs from the rotary exterior lighting control knob of the headlight switch to determine when the exterior lighting is turned ON and from the thumbwheel of the dimmer module to determine the dimming level selection.
Then the BCM provides the appropriate PWM outputs through the panel lamps dimmer circuits as well as electronic dimming level messages over the CAN data bus to other Electronic Control Units (ECUs) in the vehicle
The Instrument Panel Cluster (IPC) and the Integrated Center Stack (ICS) use the electronic dimming level messages to control the illumination intensity of their own backlighting, controls and display units.
In addition, when the interior lighting thumbwheel of the dimmer module is moved to the PARADE (or funeral) mode detent position, all of the electronic display units are illuminated at their full intensity levels for increased visibility when the vehicle is driven during daylight hours with the exterior lighting turned ON. The PARADE mode has no effect on the illumination intensity of incandescent panel lamps.